SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e8bdcaa85fda15357366b7e77ae104b5acf942b2beb2677806c064d93fad942' 
  AND token = 'kMAechijhFPMp/E0DX+U+B9+lUYLggNFFY8dQUZD2nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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