SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e90bd3206af7bdcb64c74349063b613971b12aae9e9c4f318d15da66a8b1c5' 
  AND token = 'OYwoHMwCFLYCIh6FvhUjLOhfEW0ziWCdIF9oOLp6EWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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