SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9581e277285d0f4549f91841767ee7d3e92819b8b6bbffe9d099964a54961bee' 
  AND token = 'M/9EPaW29+UP4mzCUJAwPmQDvCXpNgqysUHWS+vASeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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