SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0da8c022f758d1ddbb8e5b30e30ce6fad22e5b47a41c10fef6f051353ffb2ee' 
  AND token = 'Vs+pmgH/N3wGV2rYbZnYyjDe54dZ39u8wZnV0x5Zerk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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