SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce3620793397316c4bfba32b4daeeb5d54aba0cbbfaea356ef57ec0cb07bd9bb' 
  AND token = 'nHZ0FTnxImzLSgTCLQqlDcZs3lKEIu2LBnWks0dDI/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}