SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cca335763d321facbae62a1b66e918da95a407a2ffd21bbdfcf4fc1ebaeb5762' 
  AND token = 'giIw6RrHi3lI78q1+BpdyNe/heDOwhUVtmEt0HttZas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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