SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63f37d405a838d8e76959e01e4c80aaaf80e7596999864ecbd4789ff784a5d24' 
  AND token = '8ZFtfM9TPPOj6d6aaSIWl0cRu69lUcdfNZ5M1WS2Wj4=' 
  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"
    }
  }
}