SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0485acfba906f426285c80464732655858b086dce51698a7184c6575af770722' 
  AND token = '83SngCDokZLAjYlTaE4LDknK8/ujWIV8obspyQLi13I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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