SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f0a3ff5596b2f8b44508b11a8690748db04f3205c6a022d97d95ddd43eae397' 
  AND token = 'w5hOQx5iD2Drd+vHV4oQpFWGB/a6YOw3QB+crgRzGHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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