SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0222ee1da2c9ca195fa3fad33ec8b1f1933bf6dbe1da802f1b9b91ca748fccd' 
  AND token = '/1rxhmHXDjEv1Z2oKqOveC3jJEEP2ZAGFh/dCDATjwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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