SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57fbfca503117f340cb39da655c25640169a927a95fe6c0bb8dd7206607bdb1f' 
  AND token = 'Enn5EW/ZB1kf6y8GV2NDPNTTANpeZyBXhEJedMNhOj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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