SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e83c9c6944871a58d689c1c95eb8e5e18079a18f057760acd15fae24c281c7e' 
  AND token = 'npb/G9z6uCd7EWiKl36KLUXXBxwm6IHE++hJp3BKC7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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