SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a6cb163b8cf351fbc0a44e948d560a2709bd8fa1fea99477af8ef3cce65abe3' 
  AND token = 'OeLPfQkTGWygtCZHHB3qDOTFhPrqPjJCQ/pMlYB00Yc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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