SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '214159d22655fa7682311bd27fd5fd409c3bee9a34882ebcc7e8c562a2ed4044' 
  AND token = 'WMxL1vMmRwjScdyHz3aP/Q/wIpGt8Y4i50hPf+KF8Eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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