SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24976973549495b4a01243ff7e99d61a07830a5e15f3395fa98860894de3eafb' 
  AND token = 'rdswJUlx4+lzUCEYmZHI3zbW8upNJcefMI8m70Wjvvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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