SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f129333a1d95005f325d56416ca9018fc0d235b1e7965beb4e910c174d191e08' 
  AND token = 'PaNhTv5w/S1MDwrGZRdvyTOBuZyfPmJbblWBieio2TI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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