SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7617b9726f57665b5fb1b9561dbff0dd34439fb405879874a4820e8e03c28812' 
  AND token = 'IGsWgeR2z+pqQ1xq7xJ0F/GxZvDyrBkjQPef5h3sVrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}