SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db9d5254eacc63ccb783ecb520c6ad708c292fcffbf5278a4036ef9df01e83f2' 
  AND token = 'ohhqp5NmxxuVYlYOqb255dBS/YAhEKebtpPqETg+Pv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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