SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d320bc37156344a72913e84e5013d1c6978ede1475b037df3f32ec55d000e04' 
  AND token = 'wwZXseJTxHV0DS07LFJpk7eSw6jQgJvqYyHyTtRgsfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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