SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42cad33a8eaaec6c982c6785c8568df763a01ef1ca5567b78845ed5f6155c524' 
  AND token = 'Pua8jI+26cd+dwyXoTau7rXH9l49k5awreKFTJhk6sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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