SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41b40abc7fd552685713ebc0afa1590f1e9258a66ac21a5f9a1ecbe6fba880c1' 
  AND token = 'GZWgQdxfpik36M/mOlm+vihNv54Yp02yY1nw6tu2u90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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