SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de1a5aac050bbb61a63bff400fb111a4b72eea7dcfcc5eeaf478a809e87d0aac' 
  AND token = 'AQn8X3ICLKDiTPMsZvJugsKaj+oDYeOGwvmRunon37A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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