SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96e29c9b2cb3aa97274f91756fb965a7eff7f7425df1b38cb47c11007b023518' 
  AND token = 'xGfuccCq6A/cU1VaVfUdBdhAdGrRiiFWCjVGK1jOv3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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