SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a622f78f91805ccbe2dba49620b114fedd47c8091e6ef74d16b31eb87b36b3b7' 
  AND token = 'ELjIlysvEpuHly4fr8nFxDX9fafd3zQqBFZKf00zbTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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