SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '977f7d6d9b144b3e4b36ac7e6d62ed0956f127487254011b2a234c446ca45ebc' 
  AND token = 'Lzno7tR8BAJEyQmdYRDrFKcjmNHXPntSZuBAtoNBis4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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