SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b939dbbef2a3794297ff3b2a7a569cbe7e4aa1a572ecb841c7aa23ae2323270' 
  AND token = 'lAaW5Nns9mGc5S88tzx5wwXRhSsou96FlrbCYPbSQQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}