SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf0afd9badbb6b01147e4132e3f9728bdd3fd5e65d1526934ca6ecfab7a144e7' 
  AND token = 'KPuLG5HNVjPkDJC4uh8bGMHhOXUBrQEn1/q6JITxvbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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