SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c513af8a81d9bb6261e7ddbc2ff7e1e6021c6773591780d745b227ed94950d1' 
  AND token = 'WsSqrXyp44oqIjiIe1ZdN3yIAhxvb0b4XDGpYfleJDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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