SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a053b70620a169871084c3b6bfd7f52ccd937fe49afc4e755cfeca7b6e9aeda1' 
  AND token = '8BsDHRVhET+PLyCD17/QapiUpJoDkSkgKml9W+kwhlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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