SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '641bca991592f5e7a3b532c4c3f3b51597b4b39494883ecadfacad08ef37ccd4' 
  AND token = 'CZ2KOnTSnVTaRqpgVwMYUa5LRC9Y5I3yNg4TcJtUniU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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