SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96e1e8c345c2da577190c8a6419c4f7669e1ee0bda5b0a485df5d13fe64531e3' 
  AND token = 'X6m/ZDgt1JPkNh/BQt3ffma1A//CM9tvaWhK1p5egYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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