SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e26a60f144db456f3460898801553c76d0e12ade10f07919c6793313d281238e' 
  AND token = 'M7HXHIGQtyOaAip8Cw6al+vf7/HwDivsioaITOH2gi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}