SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '509e7c3d19ab7fb5be8709f6d6578530b4ae2ab1b85872271f7813008483b8f3' 
  AND token = 'OeY5KmES+NT71kaQYT/bEUfBrq4tTkSUbsAW3gia0xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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