SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d58860413cfd298da1c4369fd203ceeb34827489b7023493f0f053c032707f0' 
  AND token = 'asvSLVpWQVSWWLHB8HXs9NwGrRk7VDvoBd8eTm0p/7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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