SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9d97552215b4972352a1892057f35c82f30c882d82264b29f96781296a4c06b' 
  AND token = '8XPxpVqc7aJgUBpD/nTL2YTJzWY631NvTr89DJRPOfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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