SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13c452c5afebec257f8b6a35e3cd0a51483f4aa25eeb7ee7170f23df31d2a7a7' 
  AND token = 'rEFxju22TJX7h454dEnF1ox90+WgFS9yXB0kB3615/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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