SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f246ad9a534ecb4ef27058348027724f6bd22c99b0bc093e755cd1df0e85f82' 
  AND token = 'BwCiVnZmwI4JocUJV/erYNebCzvVqNqOKKxJTBkYavY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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