SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac5e167f72525314a69e27104aa54a4fd37be63c5ac693d525f903059942d075' 
  AND token = 'BovQfND3Tifa0zbMwuGsr4LHYJebmEShkRIpk3dI4go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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