SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22fad68a210ffbc0bab7b2164002801efa301a362148aafe33b6f83e97b3779f' 
  AND token = '4bpkmNRtwKZ/RNytAbbpYtXxxAwbf1wARn7LLArLTZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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