SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f239e970b15ae5f054859e1a8643b000c166c2a75c10f8df8a72aeea673f1cc' 
  AND token = 'qvRE9CzJWmbyNuLFVDibpBw1Z6VxK7mkuRSq1mAsm+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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