SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5b82b7a47318806885a289553f686eb192b4d3da0e86b840245d954a1d6afb0' 
  AND token = 'YqLRbVj8ymVwvWR4Y36hxkeCQXK1rHmoqjHJM0GlI5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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