SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c417837404df6c1680468c0efb46e9ad131a32be661f9ea7a983db1fe5b27ff6' 
  AND token = 'v/tXZe2JpKok2YV74y+bXbssDUZGarnoAUqRoM9ejsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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