SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c02e64dd7f489cde52b3b3ad1f72f89bfa140c48b3747d421a2c3968e04a5116' 
  AND token = 'VpwZRNAhR+3zEVfzvJbGqVMeIPnp2ueXvIqKhZprR94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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