SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea259c125b23fed731bf3959f13471013d353db4df448bd29cc9ea634b08814a' 
  AND token = 'WK30DfVt8LaVOVJplTRaTpClEF140FDVifxBBg114hU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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