SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53a15b06cebc87addd00e635d0ffea1219b76be66ca82198746ce2933c2a9232' 
  AND token = 'BD27JntZ/sJuqIQkWMMMVIXJ1HGTKLBh8waH/Bj7aMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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