SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9d307db4001b8a5b6fe0b8ebbe7f0f9340b6c63597c65482969284af4fc23db0' 
  AND token = 'xBBCVvHkyhqyWlQXuc36wP2VaD+SuSpiaUMYhLUP66c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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