SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433d693f2e1ee6f6ddbd3c4a4bc3c382016199e3ef7d821bd0c8bba37d5662ca' 
  AND token = 'W8H5jro2ArQHRcKxLfsEyDHV0Mr7y2UMyzv3RqF61tQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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