SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aff98f728fb825bc667c178cfb03293b3a03d06aa6ebdc77e39cd620cea7c97' 
  AND token = 'uvX3g7MOyGuJS1VGhgfvTqK3vI1dgBu7U96Yw/lh1jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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