SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c992d2fd6662752539a8b24747cdf99543167427e4e7a83fc3a61809c5b08aaf' 
  AND token = 'ZBaoB8TnGLE0RjRi0Jykk9VdgY2k9p+YzyZVjhmtRR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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