SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f6954d897db2b321149e8eef84ded8532b6fbf3a9db6ba100265bc7c0124428' 
  AND token = '+adt/OBvcqspHhs0yWdo/juHNE8SxI9XoRlAhLBbwYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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