SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8354d52d5b70102a989faca815a8c0c5d7a80d7b08c4b23079fb2c86329fbde7' 
  AND token = 'hYRNAnegFHRYmch4KYK4MA0eGTCylKqyP0Mmx29wr6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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