SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0298ead8d78aac0062c62b54e1d3059d9cb8e159a52b5d950247077cdcc9316c' 
  AND token = 'Be8g3p2GFidIn2Ql3ZQzC4MY/22nxvJlQpyjfvUntMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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