SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '520d3027b3e6d3c18040446b52c99d47f6419addd05eae86cef14b8e9a51f9ca' 
  AND token = '0puzSgEHAaYi4MvIE5SkGMbIN9i7I7/MomylRMvZHsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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