SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad2a59a272cf1134a37a9e84dd0385052c32de2865af3c5e80ddc4e507b42d1c' 
  AND token = 'Lyogu5K5HnBM7STxrYQqkUbPRyZ+8FdfDEj4yryNeOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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