SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8082befbaa4d26ce4ef85a9b94785a9b6ee106c1f08b65017044b2352a741001' 
  AND token = 'SzY1wboJoEy78gwtYJTftPxp51qo+kWGvyEFw5cAxx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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