SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee2d1492bad38472bc61f5330107ced250bd97812c0a61b617c281689c2a896a' 
  AND token = 'HF7uiID/asdb26KBSeYfgmxgueISfp8zxzReRw6gsCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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