SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f5954fdaaa187f3961aaffa724d5a0e3bbd39e8ae852316b8a3bc659a498d3' 
  AND token = 'c7Ju4IEkzEQqBAlXDm5hfK0SqZ+hg5/AvQhj7kltDH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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