SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de0ef3c69fbc1d7c38aed90fdde830f5fbc19a01acee0cb0e6dd420e591d3338' 
  AND token = '/+3YqgmWN6yUg/PPA/lK7q2Yjp78epN8Wcsb7W8hGkk=' 
  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"
    }
  }
}