SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8e5f29225be5b37e71dfc0a82410dad9d4030996f7b82894f4da17577d38d5c' 
  AND token = 'yX+soJze3OcGqOE7CUErSwBJE1fRuczZtZBR8pj/6uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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