SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b7f3076c5da26c40e83505d60868d2991332dd747222b837aceb92d8431b376' 
  AND token = 'Md1XW/57M2UR45P9aFsoblJNqzvU+TSmjwLKPzXH2fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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