SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a464e4f2f7718324da6157949593466a1e7f5c5a792a345e80586bcc31d60c02' 
  AND token = 's2S7Yp9f3t7LbuP1WDtk9Upz6BfXf9gvl5DiYHY7j5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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