SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc3ec786d8c85bf18a0a22f2dbada97b4e619fbca4180df45d284a2e9eb00cea' 
  AND token = 'Z2mZhgmn70C5BGlP7I8od9KQ2YmEjV1XjPvOV+nh/zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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