SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5e163dafa5916342491a52d4d9d78926764662c9d7fce699f81679c13a149ac' 
  AND token = '47vrqFzK3zFpwSHC3eslUraMphJyZr79+38TJHOu1sY=' 
  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"
    }
  }
}