SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db13945d6470c5176753e107500f1511154ecf9a00d87bb4c1d70f6db680bc37' 
  AND token = 'RKLFeutdajnmiInZERd6s/sVxXz9EjQjJU4RzizX/4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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