SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c862b93386d4144b030523e58269229cf28b2ea21ca09547f3d426c6d51ff66' 
  AND token = 'z7NQ/2S9xwFvlKkYwb6goqEZPKcyLnGj3Mdjgu2dfdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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