SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd976cbb0e4f003a1787592319114d513a12bfde5bff44f6145e8786dec71d1f' 
  AND token = 'afatqjFM8fhQo8CI+VqBR62gkGA1Oo43X5EpufGZNIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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