SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91e2f0f1a5173bf980d3e924d82d7f176db358bbfa4ac1f72122f28cd8d6466a' 
  AND token = 'quduklnCKiDHiIwg/r7QpHBdN1i9b9EbQitk7fb/ONU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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