SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5385cfeb2c80e7d240fcddf930382d1162fc3bebefc9ed7afa81da3bdc9ff7f7' 
  AND token = 'wI3n5nU5qb0gjWtNxfxThTGMT0Xk9AU0QcN30azzths=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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