SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac9b3fb9f9fc609caa0e3ef9efe1e1d25a09664d36cf718c4fe5546d5465818c' 
  AND token = 'L6k0vrURO8xukFpxrPA2YqxTRzxHhx1+UZXrOvWwR/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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