SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0506c2d38993a4124237d026ae930eb1578fba2c89ad1986d4faf2c03759496' 
  AND token = 'XggmXaTX5+QfmEVlDl6ZarHj87DZiUu0AcL68dg1uvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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